Organotin curing catalyst for vulcanizable organopolysiloxanes

ABSTRACT

Novel organotin curing catalysts for, e.g., the RTV organopolysiloxanes, whether single- or two-component such compositions, are comprised of admixture of (i) a diorganotin bis( beta -diketonate) and (ii) an organotin (IV) compound devoid of  beta -diketonato functional group. The silicone elastomers produced thereby are notably well adopted for use in the building industry.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to novel tin curing catalysts forconverting organopolysiloxane compositions into silicone elastomers,and, more especially, to such catalysts comprised of a mixture of adiorganotin bis(β-diketonate) and an organotin (IV) compound devoid ofany β-diketonato functional group.

2. Description of the Prior Art

A wide variety of tin compounds have already been proposed to this artas catalysts for crosslinking polyorganosiloxane compositions and inparticular RTV compositions (compositions which can be vulcanized atambient temperature) in a single pack or in two packs, otherwise knownas single- or two-component compositions.

The most commonly employed compounds are tin carboxylates, such astributyltin monooleate, tin 2-ethylhexanoate or dialkyltindicarboxylates, such as dibutyltin dilaurate and dibutyltin diacetate(see the Noll text Chemistry And Technology Of Silicones, page 337, 2ndEdition, Academic Press (1968).

In U.S. Pat. No. 3,186,963, the tin catalyst proposed for such purposeis the reaction product of a tin salt, especially dibutyltin dilaurate,with ethyl polysilicate.

According to U.S. Pat. No. 3,862,919, the tin catalyst proposed is thereaction product of a dialkyldialkoxysilane with a tin carboxylate.

According to Belgian Pat. No. 842,305, the catalyst thus proposed is thereaction product of an alkyl silicate or of an alkyl trialkoxysilanewith dibutyltin diacetate.

In U.S. Pat. No. 3,708,467 a catalytic system is described consisting ofa mixture of certain tin salts with a specific titanium chelate, in asingle-component composition.

Lastly, in published European patent application EP-A-147,323 and inU.S. Pat. Nos. 4,517,337 and 4,554,310 there is described the use ofdiorganotin bis(β-diketonates) for crosslinking neutral single-componentcompositions (U.S. Pat. No. 4,517,337 and U.S. Pat. No. 4,554,310), orfor single- and two-component compositions (EP-A-147,323).

Although EP-A-147,323 has enabled considerable progress in the searchfor a tin catalyst capable of being used both for single- andtwo-component compositions, it has become apparent that diorganotinbis(β-diketonate) compounds exhibit a core setting time which issomewhat slow, especially for two-component compositions.

In general, in the case of the single-component compositions, a basicproblem which is encountered is that of the storage stability and of theretention of the physicochemical properties (extrudability, castability,setting time) of the composition, and of retention of these sameproperties by the crosslinked material (mechanical properties, hardness,elongation, tear strength, adhesiveness, and the like).

Serious need exists in this art for a catalyst which crosslinks veryrapidly in moist air and at the surface, but which at the same timeensures a core crosslinking which is as thorough as possible, and whichis active in low concentrations, while minimizing the decompositionreactions of the crosslinked material, which are inherent in thepresence of tin.

Insofar as the product crosslinked material is concerned, the sameproblems exist in the case of the single-component compositions, but, inaddition, the process time, namely, the time during which thecomposition can be used after mixing without hardening, must besufficiently long to permit its use, but sufficiently short to produce amolded shaped article which can be handled not later than 24 hours afterits manufacture.

Such catalyst must, therefore, enable a satisfactory compromise betweenthe utilization time of the catalyzed mixture and the time after whichthe molded article can be handled. In addition, the catalyst mustprovide the catalyzed mixture with a spreading time which does not varyas a function of storage time.

Furthermore, the tensile properties of the crosslinked materials,especially hardness and tear strength, must remain stable under storage.

SUMMARY OF THE INVENTION

Accordingly, a major object of the present invention is the provision ofan improved catalyst system which can be used for crosslinking bothsingle- and two-component organopolysiloxane elastomeric compositions.

Another object of the present invention is the provision of a catalystsystem of the above type which simultaneously satisfies the constraintswhich are common to storage, application and crosslinking of bothcategories of elastomeric compositions, while at the same time solvingthe specific problems posed by each without, however, presenting anyharmful secondary or side effects in either.

Briefly, the invention features organopolysiloxane compositionscomprising, on the one hand, a base composition capable of curing into asilicone elastomer at ambient temperature and above, and, on the other,an organotin curing catalyst system which comprises a mixture of adiorganotin bis(β-diketonate) with an organic derivative of tin ofvalency IV devoid of any β-diketonato group. The latter derivativecontains at least one tin atom, each of which atoms bears two organicradicals bonded via a Sn--C bond, the remaining two valencies beingsatisfied by organic or inorganic radicals bonded via a Sn--O, or Sn--Sbond, oxygen or halogen atoms, and/or hydroxyl radicals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

More particularly according to the present invention, the diorganotinbis(β-diketonates) comprising the subject tin catalyst systems areadvantageously chelated compounds corresponding to the formula: ##STR1##wherein R¹ and R², which are identical or different, are each C₁ -C₁₂organic radicals.

More especially, such organic radicals R¹ and R² include:

(i) halogenated or nonhalogenated C₁ -C₁₂ alkyl radicals, such asmethyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl,tert-butyl, pentyl, hexyl, heptyl, 2-ethylhexyl, octyl, decyl, dodecyl,chloromethyl or 2,5-dichloroethyl radicals,

(ii) halogenated or nonhalogenated C₂ -C₈ alkenyl radicals, such asvinyl, allyl, methallyl, 2-butenyl, 2-pentenyl, 3-octenyl or5-fluoro-2-pentenyl radicals,

(iii) halogenated or nonhalogenated C₄ -C₈ cycloalkyl radicals such ascyclopentyl, cyclohexyl, methylcyclohexyl,. cyclooctyl,3,4-dichlorocyclohexyl or 2,6dibromocycloheptyl radicals,

(iv) halogenated or nonhalogenated monocyclic C₆ -C₁₀ aryl radicals,such as phenyl, tolyl, xylyl, cumenyl, chlorophenyl, dichlorophenyl,trichlorophenyl, difluorophenyl or trifluoromethylphenyl radicals,

(v) halogenated or nonhalogenated monocyclic C₇ -C₁₂ arylalkyl radicals,such as benzyl, phenylethyl, phenylpropyl or trifluoromethylphenylethylradicals,

(vi) halogenated or nonhalogenated C₁ -C₅ alkoxy radicals, such asmethoxy, ethoxy, propoxy, butoxy, pentoxy, chloromethoxy, dichloroethoxyor dichloropentoxy radicals, and

(vii) C₁ -C₆ acyloxy radicals, such as acetoxy, propanoyloxy,butanoyloxy, pentanoyloxy or hexanoyloxy radicals.

The symbols R³ and R⁵, which are identical or different, have the samemeaning as R¹ and R², namely, C₁ -C₁₂ organic radicals, and mayadditionally be halogen atoms, cyanoalkyl radicals containing a C₂ -C₄alkyl moiety, or cyanoalkoxy radicals containing a C₁ -C₅ alkoxy moiety.

Exemplary of the cyanoalkyl radicals, representative are cyanoethyl,cyanopropyl and cyanobutyl radicals, and cyanoethoxy and cyanopropoxyradicals are exemplary of the cyanoalkoxy radicals.

R⁴ is a hydrogen atom or a halogenated or nonhalogenated C₁ -C₈hydrocarbon radical.

This radical includes, more especially, halogenated or nonhalogenatedalkyl radicals, such as methyl, ethyl, propyl, butyl, hexyl and octylradicals and halogenated or nonhalogenated monocyclic aryl radicals,such as phenyl, tolyl, chlorophenyl and dichlorophenyl radicals.

In addition, R⁴ and R⁵ may together form a cyclic C₅ -C₁₂ hydrocarbonradical, substituted or unsubstituted by chloro, nitro or cyanoradicals.

Exemplary of such ring members, representative are those of theformulae: ##STR2##

Diorganotin bis(β-diketonate) is an organic tin derivative which isdescribed in the chemical literature.

Various methods for the production thereof appear, in particular, inU.S. Pat. Nos. 3,055,845 and 4,517,337 and in published European patentapplication EP-A-147,323, in the text Metal β-Diketonates And AlliedDerivatives by R. C. Mehrotra, R. Bohra and D. P. Gaur, published in1978 by Academic Press, and in the text The Chemistry Of OrganotinCompounds by R. C. Poller, published in 1970, also by Academic Press,said publications hereby being incorporated by reference.

Exemplary of such derivatives, representative are those of the formulae:##STR3##

The organotin (IV) compound, free from any β-diketonato functionalgroup, which is combined with the diorganotin bis(β-diketonate) isadvantageously selected from among the compounds of the formulae:##STR4## wherein the symbols R⁶, which are identical or different, areeach halogenated or nonhalogenated C₁ -C₂₀ hydrocarbon radicals.

More especially, such hydrocarbon radicals include:

(i) halogenated or nonhalogenated, straight or branched chain C₁ -C₂₀alkyl radicals, such as methyl, ethyl, propyl, isopropyl, butyl,isobutyl, pentyl, hexyl, 2-ethylhexyl, octyl, nonyl, decyl, undecyl,dodecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl, eicosyl,chloromethyl, 3,3,3-trifluoropropyl and 4,5-dichloropentyl radicals,

(ii) C₂ -C₁₈ alkenyl radicals, such as vinyl, allyl, 2-butenyl,4-octenyl, undecenyl, pentadecenyl and that of the formula CH₃ (CH₂)₇CH═CH(CH₂)₇ CH₂,

(iii) halogenated or nonhalogenated C₄ -C₁₀ cycloalkyl radicals, such ascyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl,dimethylcyclohexyl, cyclooctyl, chlorocyclohexyl andtrifluoromethylcyclohexyl radicals,

(iv) halogenated or nonhalogenated C₄ -C₁₀ cycloalkenyl radicals, suchas cyclopentenyl, cyclohexenyl, cyclooctenyl,2,3-difluoro-1-cyclohexenyl, methyl-2-cyclohexenyl andbutyl-2-cyclohexenyl radicals,

(v) halogenated or nonhalogenated monocyclic C₆ -C₁₅ aryl radicals, suchas phenyl, tolyl, xylyl, ethylphenyl, propylphenyl, 2,3-diethylphenyl,chlorophenyl, dichlorophenyl, trichlorophenyl, pentafluorophenyl ,trifluoromethylphenyl and 4,5-dichlorohexylphenyl radicals, and

(vi) halogenated or nonhalogenated monocyclic C₇ -C₁₅ arylalkylradicals, such as benzyl, phenylethyl, phenylpropyl, phenylbutyl,tolylethyl, xylylbutyl, 2,4,5-trichlorophenylethyl andpentafluorophenylethyl radicals.

The symbols A, which are identical or different, are each organic and/orinorganic radicals, organosilicon radicals or a diorganopolysiloxanechain, all bonded to the tin atom via a Sn--O or Sn--S bond, halogenatoms, or hydroxyl radicals. In particular, these symbols represent:

(1) monocarboxylate radicals of the formula R⁷ COO, in which R⁷ is ahalogenated or nonhalogenated C₁ -C₂₀ hydrocarbon; this may be the sameas that represented by the symbol R⁶. Thus, R⁷ includes halogenated ornonhalogenated C₁ -C₂₀ alkyl radicals, C₂ -C₁₈ alkenyl radicals,halogenated or nonhalogenated C₄ -C₁₀ cycloalkyl and cycloalkenylradicals, and halogenated or nonhalogenated monocyclic C₆ -C₁₅ aryl andarylalkyl radicals.

Specific examples of such radicals are the same as those given above forthe radicals denoted by the symbol R⁶ ;

(2) dicarboxylate radicals of the formula ##STR5## formed by couplingtwo R⁷ COO radicals.

These dicarboxylate radicals bonded to the same tin atom or to two tinatoms result in the formulae: ##STR6## in which the symbol G¹ denotes adivalent C₁ -C₁₅ hydrocarbon radical. More especially, such divalentradical includes:

(i) C₁ -C₁₅ alkylene radicals, such as methylene, ethylene, propylene,butylene, 2-ethylhexylene, nonylene, dodecylene and pentadecyleneradicals,

(ii) C₂ -C₈ alkenylene radicals, such as the radicals of the formulae:

    --CH═CH--, CH.sub.2 ═C--CH.sub.2 -- ##STR7##

    --(CH.sub.2).sub.3 CH═CH--(CH.sub.2).sub.3, --CH.sub.2 CH═CH--CH.sub.2 --,

(iii) monocyclic C₆ -C₁₂ arylene radicals, such as those of theformulae: ##STR8##

(3) dicarboxylate radicals of the formula:

    R.sup.7 OCOG.sup.1 COO

in which the symbols R⁷ and G¹ have the same meanings as the symbols R⁷and G¹ in the formulae R⁷ COO and ##STR9##

(4) alkoxy radicals of the formula R⁸ O, in which R⁸ is a C₁ -C₈hydrocarbon radical. More especially, such radical includes:

(i) C₁ -C₈ alkyl radicals, such as methyl, ethyl, propyl, isopropyl,butyl, isobutyl, tert-butyl, secondary butyl, pentyl, 2-ethylhexyl andoctyl radicals,

(ii) monocyclic C₆ -C₁₀ aryl radicals, such as phenyl, tolyl, xylyl andcumenyl radicals,

(iii) monocyclic C₇ -C₁₀ arylalkyl radicals, such as benzyl,2-phenylethyl, 3-phenylpropyl and tolylethyl radicals;

(5) organodioxy radicals of the formula: ##STR10## formed by couplingtwo R⁸ O radicals, in in which the symbol G² represents a divalent C₂-C₁₀ hydrocarbon radical.

More especially, such radical includes:

(i) C₂ -C₁₀ alkylene radicals, such as ethylene, propylene, butylene,2-ethylhexylene, decylene radicals and the radicals of the formulae--CH(CH₃)--CH(CH₃ -- and --C(CH₃)₂ --C(CH₃)₂ --, and

(ii) C₅ -C₁₀ cycloalkylene radicals, such as those of the formulae:##STR11##

(6) polyether radicals of the formula --OR⁹ (OR¹⁰)_(c) OR¹¹ in which:

the symbol R⁹ represents C₁ -C₅ alkylene radicals, such as methylene,ethylene, propylene, butylene and pentylene radicals, or the radicals ofthe formulae --CH(CH₃)--CH₂ -- or --CH₂ --CH(CH₃ --CH₂ --,

the symbol R¹⁰ represents C₂ -C₄ alkylene radicals, such as ethylene,propylene or butylene radicals, or that of the formula --CH₂--CH(CH₃)--,

the symbol R¹¹ represents C₁ -C₄ alkyl radicals, such as methyl, ethyl,propyl or butyl radicals, or C₂ -C₅ acyl radicals, such as acetyl,propionyl, butanoyl or pentanoyl radicals, and

the symbol c represents O or an integer from 1 to 55 inclusive;

(7) ketiminoxy radicals of the formula ##STR12## in which the symbolsR¹² and R¹³, which are identical or different, represent C₁ -C₁₀hydrocarbon radicals; more especially, such hydrocarbon radicalsinclude:

(i) C₁ -C₈ alkyl radicals, such as methyl, ethyl, propyl, isopropyl,butyl, 2-ethylhexyl and octyl radicals,

(ii) monocyclic C₆ -C₁₀ aryl radicals, such as phenyl, tolyl, xylyl andcumenyl radicals,

(iii) monocyclic C₇ -C₁₀ arylalkyl radicals, such as benzyl, phenylethyland phenylpropyl radicals;

(8) alkylthio radicals of the formula R¹⁴ S, in which the symbol R¹⁴represents a C₁ -C₁₀ hydrocarbon radical. In particular, this radicalincludes:

(i) C₁ -C₁₀ alkyl radicals, such as methyl, ethyl, propyl, butyl,2-ethylhexyl, octyl and decyl radicals, and

(ii) monocyclic C₆ -C₁₀ aryl radicals, such as phenyl, tolyl, xylyl,cumenyl and mesityl radicals;

(9) organodithio radicals of the formula: ##STR13## in which the symbolG² has the meaning of symbol G² in the formula ##STR14## namely, adivalent C₂ -C₁₀ hydrocarbon radical, including C₂ -C₁₀ alkyleneradicals and C₅ -C₁₀ cycloalkylene radicals;

(10) thioglycolate radicals of the formula R¹⁵ OCOCH₂ --S--, in whichthe symbol R¹⁵ represents C₁ -C₁₀ alkyl radicals, such as methyl, ethyl,propyl, butyl, pentyl, hexyl, octyl, isooctyl or decyl radicals;

(11) hydroxyl radicals;

(12) halogen atoms, such as fluorine, chlorine or bromine atoms;

(13) nitrate, sulfate and carbonate radicals; and

(14) organosilicon radicals R⁷ ₃ SiO₀.5, or a short R⁷ ₃ SiO--(R⁷ ₂SiO--)_(n) -- diorganopolysiloxane chain, R⁷ having the meaning givenfor the formula R⁷ COO--, and R⁷ is preferably a methyl radical.

The symbols Q, which are identical or different, represent C₂ -C₁₀alkylene radicals, such as ethylene, propylene, butylene, pentylene,hexylene, 2-ethylhexylene, octylene or decylene radicals.

In one preferred embodiment of the invention, the organic derivative oftin of valency IV, which is free from any β-diketonato group, isselected from those of the formulae:

    A.sub.2 SnR.sup.6.sub.2 and R.sup.6.sub.2 SnO.

The preferred radicals R⁶ are alkyl radicals and more particularlybutyl, 2-ethylhexyl and n-octyl radicals.

The preferred radicals A are the radicals (1), (4), (7) and (14)described above and more particularly the radicals (1).

The preferred organic tin derivatives which are devoid of anyβ-diketonato group are di-n-butyltin dilaurate, di-n-octyltin dilaurate,di-n-butyltin diacetate, di-n-octyltin diacetate, di-n-butyltindi-2-ethylhexanoate, di-n-octyltin di-2-ethylhexanoate, di-n-butyltindiversatate and di-n-octyltin diversatate.

Exemplary of the compounds of the formula A₂ SnR⁶ ₂, representative arethose of the following formulae:

A=Carboxylate radicals:

    (CH.sub.3 COO).sub.2 Sn(CH.sub.3).sub.2,

    (CH.sub.3 COO).sub.2 Sn(n--C.sub.4 H.sub.9).sub.2,

    (CH.sub.3 COO).sub.2 Sn(n--C.sub.8 H.sub.17).sub.2,

    [CH.sub.3 (CH.sub.2).sub.8 COO].sub.2 Sn(CH.sub.3).sub.2,

    [CH.sub.3 (CH.sub.2).sub.3 CH(C.sub.2 H.sub.5)COO].sub.2 Sn(CH.sub.3).sub.2,

    (CH.sub.3 COO).sub.2 Sn(CH.sub.2 C.sub.6 H.sub.5).sub.2,

    [CH.sub.3 (CH.sub.2).sub.3 CH(C.sub.2 H.sub.5)COO].sub.2 Sn(n--C.sub.4 H.sub.9).sub.2,

    [CH.sub.3 (CH.sub.2).sub.14 COO].sub.2 Sn(n--C.sub.4 H.sub.9).sub.2,

    [CH.sub.3 (CH.sub.2).sub.3 CH(C.sub.2 H.sub.5)COO].sub.2 Sn(n--C.sub.8 H.sub.17).sub.2,

    [CH.sub.3 (CH.sub.2).sub.7 CH═CH(CH.sub.2).sub.7 COO].sub.2 Sn(n--C.sub.4 H.sub.9).sub.2,

    [CH.sub.3 (CH.sub.2).sub.12 COO].sub.2 Sn(C.sub.2 H.sub.5).sub.2,

    [CH.sub.3 (CH.sub.2).sub.10 COO]Sn(n--C.sub.4 H.sub.9).sub.2,

    [CH.sub.3 (CH.sub.2).sub.10 COO].sub.2 Sn(n--C.sub.8 H.sub.17).sub.2.

The dialkyltin versatates described in British Pat. No. 1,289,900.

A=Dicarboxylate radicals: ##STR15##

    (C.sub.8 H.sub.17 OCO--CH═CH--COO).sub.2 Sn(n--C.sub.4 H.sub.9).sub.2.

A=Alkoxy radicals:

    (CH.sub.3 O).sub.2 Sn(n--C.sub.4 H.sub.9).sub.2,

    (C.sub.4 H.sub.9 O).sub.2 Sn(n--C.sub.4 H.sub.9).sub.2,

    (C.sub.2 H.sub.5 O).sub.2 Sn(n--C.sub.4 H.sub.9).sub.2, ##STR16##

    [(CH.sub.3).sub.2 CHO].sub.2 Sn(C.sub.6 H.sub.5)(n--C.sub.4 H.sub.9),

    (CH.sub.3 O).sub.2 Sn(C.sub.2 H.sub.5)(CH.sub.3),

    [CH.sub.3 (CH.sub.2).sub.3 CH(C.sub.2 H.sub.5)CH.sub.2 O].sub.2 Sn(CH═CH.sub.2)(C.sub.6 H.sub.5),

A=Organodioxy radicals: ##STR17##

A=Polyether radicals:

    (CH.sub.3).sub.2 Sn(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.2,

    (C.sub.2 H.sub.5).sub.2 Sn[OCH.sub.2 --CH(CH.sub.3 (OCH.sub.3 ].sub.2,

    (C.sub.4 H.sub.9).sub.2 Sn[O(CH.sub.2).sub.3 (OCH.sub.2 CH.sub.2)5OC.sub.2 H.sub.5 ](OC.sub.2 H.sub.5),

    (C.sub.8 H.sub.17)2Sn[O(CH.sub.2l ).sub.3 (OCH.sub.2l CH.sub.2 l ).sub.3 (OCH.sub.2 l CH(CH.sub.3 l )).sub.3 OCOCH.sub.3 ](OCOCH.sub.3),

A=Ketiminoxy radicals:

    (C.sub.8 H.sub.17).sub.2 Sn[ON═C--(CH.sub.3)C.sub.2 H.sub.5 ].sub.2,

    (n--C.sub.4 H.sub.9).sub.2 Sn[ON═C(CH.sub.3).sub.2 ].sub.2

    (CH.sub.3).sub.2 Sn[ON═C(CH.sub.3)(C.sub.6 H.sub.5)].sub.2

    (n--C.sub.4 H.sub.9).sub.2 Sn[ON═C(CH.sub.3).sub.2 ](OC.sub.2 H.sub.5),

A=Alkylthio radicals:

    (CH.sub.3).sub.2 Sn(SCH.sub.3).sub.2,

    (CH.sub.3).sub.2 Sn(SC.sub.4 H.sub.9).sub.2,

    (C.sub.6 H.sub.5).sub.2 Sn(SC.sub.6 H.sub.5).sub.2,

A=Organodithio radicals: ##STR18##

A=Thioglycolate radicals:

    (C.sub.8 H.sub.17 OCOCH.sub.2 --S).sub.2 Sn(C.sub.4 H.sub.9).sub.2

A=Hydroxyl radicals:

    (C.sub.3 H.sub.7).sub.2 Sn(OH)No.sub.3

A=Halogen atoms:

    (C.sub.2 H.sub.5).sub.2 SnF.sub.2,

    (tertio-C.sub.4 H.sub.9).sub.2 SnCl.sub.2,

    (iso-C.sub.3 H.sub.7).sub.2 SnBr.sub.2,

    (CH.sub.2 ═CH).sub.2 SnCl.sub.2,

    (CH.sub.3 CCl═CH-CH.sub.2).sub.2 SnCl.sub.2,

    (C.sub.4 H.sub.9)(C.sub.6 H.sub.5)SnCl.sub.2,

    C.sub.6 H.sub.5 (CH.sub.2 ═CH)SnCl.sub.2 l

A=Nitrate, sulfate and carbonate radicals:

    (CH.sub.3).sub.2 Sn(NO.sub.3).sub.2,

    (CH.sub.3).sub.2 SnSO.sub.4,

    (C.sub.4 H.sub.9).sub.2 Sn(CO.sub.3).sub.2,

Exemplary of the compounds of the formulae:

    R.sup.6.sub.2 SnO

    AR.sup.6.sub.2 Sn--O--Sn--R.sup.6.sub.2 A ##STR19## representative are the following:

    (C.sub.2 H.sub.5).sub.2 SnO, (CH.sub.3).sub.2 SnO, (C.sub.6 H.sub.5).sub.2 SnO,

    (C.sub.4 H.sub.9).sub.2 SnO, C.sub.6 H.sub.5 O(C.sub.4 H.sub.9).sub.2 Sn--O--Sn(C.sub.4 H.sub.9).sub.2 (OC.sub.6 H .sub.5),

    Cl(C.sub.4 H.sub.9).sub.2 Sn--O--Sn(C.sub.4 H.sub.9).sub.2 Cl,

    Cl(CH.sub.3).sub.2 Sn--O--Sn(CH.sub.3).sub.2 Cl, ##STR20##

The preparation of these organic tin derivatives is known and appears,in particular, in aforementioned text, The Chemistrv Of OrganotinCompounds by R. C. Poller, published in 1970 by Academic Press, in thethree-volume work "Organotin compounds", edited by Albert K. Sawyer andpublished in 1972 by Marcel Dekker, and in the collective work edited byA. Seyferth and R. B. King, published by Elsevier Scientific PublishingCompany, a collection entitled Organometallic Chemistry Reviews, "AnnualSurveys: Silicon-Germanium-Tin-Lead".

The formulation of the mixture of diorganotin bis-(β-diketonate),hereinafter designated a chelated derivative, with the organic tin (IV)derivative evoid of any β-diketonate functional group, hereinafterdesignated a nonchelated derivative, may be carried out at ambienttemperature, by merely incorporating one of the compounds in the other.This is preferably done in the absence of moisture. The entire mixtureis stirred for a few minutes to homogenize the liquid mass. This methodis used when both tin derivatives are liquid.

In the case where two derivatives are used, one being solid and theother liquid, it may be necessary to slightly heat the mixture to about40°-80° C. to dissolve the solid derivative.

In the case where two solid derivatives are used, heating is necessary,at least to the melting temperature of one of the two tin derivatives.

The respective amounts of the two components constituting the mixtureare (in percentages by weight based on the combination of both tinderivatives) 0.1 to 99.9%, preferably 1 to 99%, of the chelatedderivative, and 99.9 to 0.1%, preferably 99 to 1%, of the nonchelatedderivative, and still more preferably 90 to 10%.

The final catalyst mixture is stable when stored at ambient temperaturein a closed container. It is used to permit or promote the curing oforganopolysiloxane base compositions into silicone elastomers at ambienttemperature and temperatures above ambient.

These base compositions are well known to this art and are employed,frequently after catalysis by a metal derivative of a carboxylic acid,for the manufacture of seals, of water-repellent coatings, molds,coating materials, for bonding and assembling a very wide variety ofmaterials, for coating organic and inorganic fibers, etc.

These base compositions may be of the single-component type, that is tosay, stable in storage in the absence of moisture and capable of beingcured in the presence of moisture, in particular of moisture provided bythe surrounding air or by water generated within the base when it isused.

Base compositions of this type may be prepared by mixing:

(A¹) 100 parts by weight of an α, ω, -dihydroxydiorganopolysiloxanepolymer having a viscosity of 700 to 1,000,000 mPa.s at 25° C.,comprising a sequence of diorganosiloxy recurring units of the formulaT₂ SiO in which the symbols T, which are identical or different,represent hydrocarbon radicals containing from 1 to 10 carbon atoms,either unsubstituted or substituted by halogen atoms or cyano groups;

(B¹) 0.5 to 20 parts by weight of a crosslinking agent selected fromamong organosilicon compounds containing more than two hydrolyzableradicals bonded to the silicon atoms, per molecule;

(C¹) 0 to 250 parts by weight of inorganic fillers; and

(D¹) 0 to 20 parts by weight of an adhesion promoter.

The α, ω-dihydroxydiorganopolysiloxane polymers having a viscosity of700 to 1,000,000 mPa.s at 25° C., preferably 1,000 to 700,000 mPa.s at25° C., are advantageously linear polymers consisting essentially ofdiorganosiloxy recurring units of the above-mentioned formula T₂ SiO,and blocked by a hydroxyl group at each end of their polymer chain;however, the presence of monoorganosiloxy recurring units of the formulaTSiO₁.5 and/or of siloxy recurring units of the formula SiO₂ is notexcluded, in a proportion not exceeding 2% based on the number ofdiorganosiloxy recurring units.

The hydrocarbon radicals containing from 1 to 10 carbon atoms, whetherunsubstituted or substituted by halogen atoms or cyano groups, denotedby the symbols T, include:

(i) alkyl and haloalkyl radicals containing from 1 to 10 carbon atoms,such as methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl,2-ethylhexyl, octyl, decyl, 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyland 3,3,4,4,4-pentafluorobutyl radicals,

(ii) cycloalkyl and halocycloalkyl radicals containing from 1 to 10carbon atoms, such as cyclopentyl, cyclohexyl, methylcyclohexyl,propylcyclohexyl, 2,3-difluorocyclobutyl and3,4-difluoro-5-methylcycloheptyl radicals,

(iii) alkenyl radicals containing from 2 to 4 carbon atoms, such asvinyl, allyl and 2-butenyl radicals,

(iv) monocyclic aryl and haloaryl radicals containing from 6 to 10carbon atoms, such as phenyl, tolyl, xylyl, chlorophenyl, dichlorophenyland trichlorophenyl radicals, and

(v) cyanoalkyl radicals in which the alkyl moieties contain from 2 to 3carbon atoms, such as β-cyanoethyl and γ-cyanopropyl radicals. Methyl,phenyl, vinyl and 3,3,3-trifluoropropyl radicals are the preferredradicals.

Exemplary of the recurring units of the formula T₂ SiO, representativeare those of the formulae:

    (CH.sub.3).sub.2 SiO,

    CH.sub.3 (CH.sub.2 ═CH)SiO,

    CH.sub.3 (C.sub.6 H.sub.5)SiO,

    (C.sub.6 H.sub.5).sub.2 SiO,

    CF.sub.3 CH.sub.2 CH.sub.2 (CH.sub.3)SiO,

    NC--CH.sub.2 CH.sub.2 (CH.sub.3)SiO,

    NC--CH(CH.sub.3)CH.sub.2 (CH.sub.2 ═CH)SiO,

    NC--CH.sub.2 CH.sub.2 CH.sub.2 (C.sub.6 H.sub.5)SiO.

It will be appreciated that the polymer (A¹) may be a mixture ofα,ω-dihydroxydiorganopolysiloxane polymers which differ from each otherin molecular weight and/or in the nature of the groups bonded to thesilicon atoms.

These α,ω-dihydroxydiorganopolysiloxane polymers (A¹) are commerciallyavailable; in addition, they can be readily prepared using methods whichare well known to this art.

The crosslinking agents (B¹) are present in a proportion of 0.5 to 20parts, preferably 1 to 18 parts, per 100 parts ofα,ω-dihydroxydiorganopolysiloxane polymers (A¹). They are organosiliconcompounds containing more than two hydrolyzable radicals bonded to thesilicon atoms, per molecule.

Exemplary of suitable hydrolyzable radicals, representative areN-substituted amino, N-substituted amido, N,N-disubstituted aminoxy,ketiminoxy, aldiminoxy, alkoxy, alkoxyalkyleneoxy, enoxy and acyloxyradicals.

Preferably, the crosslinking agent has the general formula:

    Y.sub.f SiW.sub.g Z.sub.4 -f-g

in which:

the symbol Y represents a C₁ -C₁₀ hydrocarbon radical, whetherunsubstituted or substituted by halogen atoms or cyano groups,

the symbols Z, which are identical or different, represent hydrolyzableradicals selected from among those of the formulae: ##STR21## in whichthe symbols Z¹, which are identical or diffeent, represent C₁ -C₁₅hydrocarbon radicals, the symbols Z₂, which are identical or different,represent C₁ -C₈ hydrocarbon radicals, and the symbol E¹ represents a C₄-C₈ alkylene radical,

the symbols W, which are identical or different, represent alkoxyradicals of the formulae Z³ O and Z³ OE² O, in which the symbol Z³represents a C₁ -C₄ alkyl radical and the symbol E₂ a C₂ -C₄ alkyleneradical,

the symbol f represents zero or one, and

the symbol g represents zero, 1 or 2.

The symbol Y may have the same meaning as the symbol T in theaforementioned recurring units of the formula T₂ SiO; thus, theillustration given for T is also applicable to Y.

The symbols Z¹ represent C₁ -C₁₅ hydrocarbon radicals which include:

(i) C₁ -C₁₅ alkyl radicals, such as methyl, ethyl, propyl, 2-ethylhexyl,octyl, decyl, dodecyl or pentadecyl radicals,

(ii) C₅ -C₁₀ cycloalkyl radicals, such as cyclopentyl, cyclohexyl,methylcyclohexyl, dimethylcyclohexyl, propylcyclohexyl and cycloheptylradicals,

(iii) monocyclic C₆ -C₁₀ aryl radicals, such as phenyl, tolyl or xylylradicals, and

(iv) C₂ -C₁₅ alkenyl radicals, such as octenyl, undecenyl ortetradecenyl radicals.

The symbols Z² represent C₁ -C₈ hydrocarbon radicals which include, inparticular:

(i) C₁ -C₈ alkyl radicals, such as methyl, ethyl, propyl, isopropyl,butyl, isobutyl, 2-ethylhexyl or octyl radicals,

(ii) C₅ -C₈ cycloalkyl radicals, such as cyclopentyl, cyclohexyl ormethylcyclohexyl radicals, and

(iii) monocyclic C₆ -C₈ aryl radicals, such as phenyl, tolyl or xylylradicals.

The symbol Z³ represents a C₁ -C₄ alkyl radical, such as the methyl,ethyl, propyl or butyl radical.

The symbol E¹ represents a C₄ -C₈ alkylene radical which may correspondto the formulae: (CH₂)₄, (CH₂)₅, (CH₂)₆, (CH₂)₇, --CH₂ --CH(C₂ H₅)(CH₂)₃--and --CH₂ --CH₂, --CH(CH₃)CH ₂ CH₂ --.

The symbol E² represents a C² --C₄ alkylene radical which may correspondto the formulae: (CH₂)₂, --CH(CH₃)--CH₂ --CH(CH₃)CH ₂ CH₂ --and--CH(CH₃)--CH(CH₃)--.

The crosslinking agents B¹ of formula Y_(f) SiW_(g) Z₄ -f-g are used inthe preparation of commercial single-component organopolysiloxanecompositions, and are widely described in the chemical literature.

By way of example, there are mentioned below:

(1) silanes corresponding to the formula Y_(f) SiZ_(4-f) which followsfrom the preceding formula when g=zero, and

(2) patents which describe these:

    Z═Z.sup.1 COO--:

    CH.sub.3 Si(OCOCH.sub.3).sub.3, C.sub.2 H.sub.5 Si(OCOCH.sub.3).sub.3,

    CH.sub.2 ═CHSi(OCOCH.sub.3).sub.3, C.sub.6 H.sub.5 Si(OCOCH.sub.3).sub.3,

    CH.sub.3 Si[OCOCH(C.sub.2 H.sub.5)(CH.sub.2).sub.3 --CH.sub.3 ].sub.3,

    CF.sub.3 CH.sub.2 CH.sub.2 Si(OCOC.sub.6 H.sub.5).sub.3, CH.sub.3 Si(OCOC.sub.6 H.sub.5).sub.3,

    CH.sub.3 Si(OCOCH.sub.3).sub.2 OCOCH(C.sub.2 H.sub.5)(CH.sub.2).sub.3 CH.sub.3,

    CH.sub.3 COOSi[OCOCH(C.sub.2 H.sub.5)(CH.sub.2).sub.3 CH.sub.3 ].sub.3, ##STR22##

    CN--CH.sub.2 CH.sub.2 Si(OCOCH.sub.3).sub.3

French Pat. Nos. 1,198,749, 1,220,348, 2,464,288.

    Z═(Z.sup.2).sub.2 C═NO ##STR23##

    CH.sub.3 Si[ON═C(CH.sub.3).sub.2 ].sub.3 , CH.sub.3 Si[ON═C(CH.sub.3)C.sub.2 H.sub.5 ].sub.3,

    CH.sub.2 ═CHSi[ON═C(CH.sub.3)C.sub.2 H.sub.5 ].sub.3 , C.sub.6 H.sub.5 Si[ON═C(CH.sub.3).sub.2 ].sub.3,

    CH.sub.3 Si[ON═C(C.sub.2 H.sub.5)(CH.sub.2).sub.3 CH.sub.3 ].sub.3,

    CH.sub.3 Si[ON═C(CH.sub.3)CH.sub.2 CH(C.sub.2 H.sub.5)(CH.sub.2).sub.3 CH.sub.3 ].sub.2,

    (CH.sub.3).sub.2 C═NOSi[ON═C(CH.sub.3)C.sub.2 H.sub.5 ].sub.3, ##STR24##

French Pat. Nos. 1,314,649, 1,371,250, 2,074,144.

    Z═Z.sup.1 CON(Z.sup.1)-- ##STR25##

    CH.sub.3 Si[N(CH.sub.3)COCH.sub.3 ].sub.3,

    CH.sub.3 Si[N(C.sub.6 H.sub.5)COCH.sub.3 ].sub.3,

    CF.sub.3 CH.sub.2 CH.sub.2 Si[N(C.sub.6 H.sub.5)COCH.sub.3 ].sub.3,

    CH.sub.2 ═CH--si[N(CH.sub.3)COC.sub.6 H.sub.5 ].sub.3, ##STR26##

French Pat. Nos. 1,423,477, 2,201,326.

    Z═Z.sup.1 NH--:

    CH.sub.3 Si--(NH n--C.sub.4 H.sub.9).sub.3 ##STR27##

    C.sub.6 H.sub.5 Si(NH iso.C.sub.4 H.sub.9).sub.3 ##STR28##

    CH.sub.2 ═CHSi (NH iso.C.sub.4 H.sub.9).sub.3

French Pat. Nos. 1,248,826, 1,510,778, 2,201,327.

    Z═Z.sup.1 NH and (Z.sup.2).sub.2 C═NO--: ##STR29##

CH₂ ═CHSi(NH n--C₄ H₉)₂ [ON═(C₂ H₅)CH₃ ]

Noted below, by way of examples, are: (1) silanes corresponding to theformula Y_(f) SiW_(g) Z_(4-f-g) in which g denotes 1 or 2.

    Z═Z.sup.1 COO--:

    W═Z.sup.3 OE.sup.2 O--:

    CH.sub.3 Si(OCH.sub.3)(OCOCH.sub.3).sub.2, ##STR30##

    CH.sub.2 ═CHSi(OCH.sub.2 CH.sub.2 OCH.sub.3)(OCOCH.sub.3).sub.2,

    (CH.sub.3).sub.3 COSi(OCOCH.sub.3).sub.3, ##STR31##

    W═Z.sup.3 O and Z.sup.3 OE.sup.2 O--:

    CH.sub.3 Si(OC.sub.2 H.sub.5)[ON═C(CH.sub.3).sub.2 ].sub.2,

    CH.sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3)[ON═C(CH.sub.3).sub.2 ].sub.2,

    CH.sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.2 [ON═C(CH.sub.3)C.sub.2 H.sub.5 ]

    Z═Z.sup.1 CON (Z.sup.1 --and ##STR32##

    W═Z.sup.3 O--:

    CH.sub.3 Si(OCH.sub.3)[N(CH.sub.3)COCH.sub.3 ].sub.2,

    CH.sub.3 Si(OC.sub.2 H.sub.5)[N(CH.sub.3)COC.sub.6 H.sub.5 ].sub.2,

    CH.sub.3 Si(OC.sub.2 H.sub.5).sub.2 [N(CH.sub.3)COC.sub.6 H.sub.5 ], ##STR33##

    Z═Z.sup.1 NH-- and Z.sup.1 COO--:

    W═Z.sup.3 O--:

    (C.sub.2 H.sub.5 O).sub.2 Si(OCOCH.sub.3)[NHCH(CH.sub.3).sub.2 ]

These mixed silanes are described, more particularly, in French patentof first addition No. 90,695 to French Pat. No. 1,423,477, and in FrenchPat. Nos. 1,439,025, 1,541,542, 1,541,543 and 2,067,636.

The inorganic fillers (C¹) are used in a proportion of 0 to 250 parts,preferably 5 to 200 parts, per 100 parts of theα,ω-dihydroxydiorganopolysiloxane polymers (A¹).

These fillers may be in the form of very finely divided materials whosemean particle diameter is less than 0.1 micrometer. These fillersinclude pyrogenic silicas and precipitated silicas; their BET specificsurface area is generally greater than 40 m^(2/) g.

These fillers may also be in the form of more coarsely dividedmaterials, with a mean particle diameter greater than 0.1 micrometer. Asexamples of such fillers, representative are ground quartz, diatomaceoussilicas, calcium carbonate, calcined clay, rutile-type titanium oxide,iron, zinc, chromium, zirconium and magnesium oxides, the various formsof alumina (hydrated or otherwise), boron nitride, lithopone, bariummetaborate, barium sulfate and ballotini; their specific surface area isgenerally less than 30 m^(2/) g.

The surfaces of these fillers (C¹) may have been modified by beingtreated with the various organosilicon compounds usually employed forthis purpose. Thus, such organosilicon compounds may beorganochlorosilanes, diorganocyclopolysiloxanes, hexaorganodisiloxanes,hexaorganodisilazanes or diorganocyclopolysilazanes (French Pat. Nos.1,126,884, 1,136,885, 1,236,505; British Pat. No. 1,024,234). In themajority of cases, the treated fillers contain from 3 to 30% of theirweight as organosilicon compounds.

The fillers (C¹) may be a mixture of several types of fillers ofdifferent particle size distribution; thus, they may include 30 to 70%of finely divided silicas having a BET specific surface area of morethan 40 m^(2/) g and 70 to 30% of more coarsely divided silicas having aspecific surface area of less than 30 m^(2/) g.

An adhesion promoter (D¹) may also be added, in a proportion of 0 to 20parts, preferably 0.2 to 15 parts, per 100 parts of theα,ω-dihydroxydiorganopolysiloxane oils (A¹). This agent is preferablyselected from among organosilicon compounds which at the same timecontain (1) organic groups substituted by radicals selected from amongamino, ureido, isocyanato, epoxy, alkenyl, isocyanurate, hydantoyl andmercapto ester radicals, and (2) hydrolyzable groups bonded to thesilicon atoms.

By way of illustration, exemplary organosilicon compounds are thosehaving the following formulae (including the patents describing same):##STR34##

Other single-component base composition may be perepared by mixing:

(A²): 100 parts of an α,ω-dihydroxydiorganopolysiloxane polymer having aviscosity of 700 to 1,000,000 of mPa.s at 25° C.,

(B¹): 0.5 to 20 parts of a polyalkoxysilane of the formula M_(h)SiW_(4-h), in which:

the symbol M represents a halogenated or nonhalogenated C₁ -C₁₀hydrocarbon radical,

the symbols W, which are identical or different, represent alkoxy orpolyalkoxy radicals of the formulae Z³ O and Z³ OE², in which the symbolZ³ represents a C₁ -C₄ alkyl radical, and the symbol E a C₂ -C₄ alkyleneradical, and

the symbol h is 0 or 1,

(C²): 0 to 250 parts of inorganic fillers, and

(D²): 0.5 to 15 parts of a compound selected from among:

1. primary or secondary organic amines which have a pK_(b) of less than5 in an aqueous medium, aminoorganosilanes and aminoorganopolysiloxanescontaining, per molecule, (i) at least one C₁ -C₁₅ organic group bondedto the silicon atom via a Si--C bond and substituted by at least oneamino radical and (ii) at least one C₁ -C₁₅ alkoxy or C₃ -C₆alkoxyalkylenoxy radical,

2. organic titanium and zirconium derivatives containing organoxy and/orβ-diketonato groups.

The α,ω-dihydroxydiorganopolysiloxane polymer (A²) are similar to theα,ω-dihydroxydiorganopolysiloxane polymer (A¹) described above. Suchpolymers are preferably those having a viscosity of 1,000 to 500,000mPa.s at 25° C., in which at least 80% of the radicals bonded to thesilicon atoms are methyl radicals.

From 0.5 to 20 parts, preferably 1 to 18 parts of a polyalkoxysilane ofabove-mentioned formula M_(h) SiW_(4-h) are used per 100 parts of thispolymer. The symbol M in this formula represents a halogenated ornonhalogenated C₁ -C₁₀ hydrocarbon radical which includes, moreparticularly:

(i) C₁ -C₅ alkyl radicals, such as methyl, ethyl, propyl, isopropyl,butyl, isobutyl, tert-butyl, n-pentyl, isopentyl and3,3,3-trifluoropropyl radicals,

(ii) C₂ -C₄ alkenyl radicals, such as vinyl, allyl or 2-butenylradicals,

(iii) C₅ -C₈ cycloalkyl radicals, such as cyclopentyl, cyclohexyl ormethylcyclohexyl radicals, and

(iv) the monocyclic C₆ -C₁₀ aryl radicals, such as phenyl, tolyl, xylylor chlorophenyl radicals.

The symbols W, which are identical or different, have the same meaningof the symbols W in the formula (Y)_(f) SiW_(g)(Z)_(4-f-g), describedabove. Accordingly, they represent alkoxy or polyalkoxy radicals of theformulae: Z³ O and Z³ OE² O, in which the symbol Z³ represents a C₁ -C₄alkyl radical, such as the methyl, ethyl, propyl or butyl radical, andthe symbol E² a C₂ -C₄ alkylene radical capable of corresponding to theformulae: (CH₂)₂, --CH(CH₃)CH₂ -- or --CH(CH₃)CH(CH₃)--.

As specific examples of the polyalkoxysilanes of the formula (B²)M_(h)SiW_(4-h), representative are those of the formulae:

    Si(OCH.sub.3).sub.4,

    CH.sub.3 Si(OCH.sub.3).sub.3,

    CH.sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3,

    CH.sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.3).sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.4,

    CH.sub.2 ═CHSi(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3,

    C.sub.6 H.sub.5 Si(OCH.sub.3).sub.3,

    C.sub.6 H.sub.5 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3,

    Si(OCH.sub.3).sub.2 [OCH(CH.sub.3)CH.sub.2 OCH.sub.3 ].sub.2,

    CH.sub.2 ═CHSi(OCH.sub.3).sub.3,

    CH.sub.2 ═CHSi(OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.3).sub.3,

    CH.sub.2 ═CH--CH.sub.2 Si(OCH.sub.3).sub.3,

    CH.sub.2 ═C(CH.sub.3)CH.sub.2 Si(OCH.sub.3).sub.3,

    CH.sub.2 ═CH--Si(OCH.sub.3).sub.2 [OCH(CH.sub.3)CH.sub.2 OCH.sub.3 ]

The inorganic fillers (C²) are similar to the inorganic fillers (C¹)described above.

The compounds (D²) are used in a proportion of 0.5 to 15 parts,preferably 0.8 to 13 parts, per 100 parts ofα,ω-dihydroxydiorganopolysiloxane polymers (A²). As above-indicated,they may be selected from among the primary or secondary organic amineswhich have a pK_(b) of less than 5 in an aqueous medium. Such amines maybe aliphatic, alicyclic, heterocyclic or arylaliphatic.

As specific examples of such aliphatic amines, representative aren-butylamine, amylamine, the amines of the formulae: ##STR35## and

    CH.sub.3 --CH.sub.2 --C(CH.sub.3).sub.2 NH.sub.2,

n-hexylamine, n-decylamine, laurylamine, hexadecylamine, n-octylamine,diisopropylamine, di-n-butylamine, diisobutylamine, di-n-hexylamine,ethylenediamine, propylenediamine, hexamethylenediamine, and polyaminesof the formulae: ##STR36##

    H(NHCH.sub.2 CH.sub.2).sub.2 NH.sub.2,

    H(HNCH.sub.2 CH.sub.2).sub.3 NH.sub.2,

    H.sub.2 NCH.sub.2 CH(NH.sub.2)CH.sub.2 NH.sub.2,

As specific examples of such alicyclic amines, representative arecyclopentylamine, cyclohexylamine and the amines of the formulae:##STR37##

As specific examples of such heterocyclic amines, representative arepiperidine, pyrrolidine, piperazine, and the amines of the formulae:##STR38##

As specific examples of such arylaliphatic amines, representative arebenzylamine and phenylethylamine.

All of the aforenoted organic amines are known compounds, as are variousprocesses by which they are prepared; furthermore, many of them arecommercially available on an industrial scale.

The compounds (D²) may also be selected from among aminoorganosilanesand aminoorganopolysiloxanes containing, per molecule, (i) at least oneC₁ -C₁₅ organic group bonded to the silicon atom via a SiC bond andsubstituted by at least one amino radical, and (ii) at least one C₁ -C₅alkoxy or C₃ -C₆ alkoxyalkylenoxy radical.

As specific examples of these organoaminosilanes, representative arethose of the formulae given below, in which the organic groupsubstituted by at least one amino radical is a hydrocarbon group:

    H.sub.2 N(CH.sub.2).sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3,

    H.sub.2 N(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    H.sub.2 N(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3

    H.sub.2 N(CH.sub.2).sub.4 Si(OCH.sub.3).sub.3,

    H.sub.2 NCH.sub.2 CH(CH.sub.3)CH.sub.2 CH.sub.2 SiCH.sub.3 (OCH.sub.3).sub.2,

    H.sub.2 NCH.sub.2 Si(OCH.sub.3).sub.3,

    HN(n--C.sub.4 H.sub.9)CH.sub.2 Si(OCH.sub.3).sub.3

    H.sub.2 N(CH.sub.2).sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    H.sub.2 N(CH.sub.2).sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3

    CH.sub.3 NH(CH.sub.2).sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    H(NHCH.sub.2 CH.sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3, ##STR39##

    H.sub.2 N(CH.sub.3)3Si(OCH.sub.2 CH.sub.2 OCH.sub.2 OCH.sub.3).sub.3, ##STR40##

The preparation of these silanes is described, more especially, in U.S.Pat. Nos. 2,754,311, 2,832,754, 2,930,809 and 2,971,864.

As specific examples of the organoaminosilanes, representative are thoseof the formulae given below, in which the organic group substituted byat least one amino radical is a hydrocarbon group containing ether orthioether linkages:

    H.sub.2 N(CH.sub.2).sub.3 O(CH.sub.2).sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3,

    H.sub.2 N(CH.sub.2).sub.3 O(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    C.sub.2 H.sub.5 NH(CH.sub.2).sub.3 O(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    H.sub.2 N--CH.sub.2 --CH(CH.sub.3)CH.sub.2 O(CH.sub.2).sub.3 SiC.sub.6 H.sub.5 (OCH.sub.3).sub.2,

    H.sub.2 N--CH.sub.2 CH.sub.2 NH(CH.sub.2).sub.3 O(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    H.sub.2 N(CH.sub.2).sub.2 S(CH.sub.2).sub.3 Si(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3,

    H.sub.2 N(CH.sub.2).sub.2 S(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    H(NHCH.sub.2 CH.sub.2).sub.2 S(CH.sub.2).sub.3 SiCH.sub.3 (OCH.sub.3).sub.2,

The preparation of these silanes is described, in particular, in U.S.Pat. Nos. 3,341,563, 3,551,375, 3,598,853 and 3,488,373.

The aminoorganopolysiloxanes which can be used may be prepared bycondensation of the above-mentioned aminoorganosilanes, and moreparticularly of the trialkoxyaminoorganosilanes, such as those offormulae:

    H.sub.2 N(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3,

    H.sub.2 N(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

    H.sub.2 N(CH.sub.2).sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3,

with a dihydroxydiorganopolysiloxane polymer of the class of theabove-mentioned polymers (A¹) and (A²).

Aminoorganopolysiloxanes prepared according to this process aredescribed, in particular, in U. S. Pat. No. 3,686,375, EuropeanApplication No. 50,453 and French Pat. Nos. 1,381,590, 1,385,693 and2,228,814.

As specific examples of these polymers, representative are those of theformulae:

    H.sub.2 N(CH.sub.2).sub.3 Si(OCH.sub.3).sub.2 [OSi(CH.sub.3).sub.2 ].sub.n OSi(OCH.sub.3).sub.2 (CH.sub.2).sub.3 nh.sub.2

    H.sub.2 N(CH.sub.2).sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.2 [OSi(CH.sub.3).sub.2 ].sub.n OSi(OCH.sub.3).sub.2 (CH.sub.2).sub.3 NH(CH.sub.2).sub.2 NH.sub.2

=2 to 60.

The compounds (D²) may also be organic titanium and zirconiumderivatives containing organoxy and/or β-diketonato groups bonded to thesilicon atoms.

As specific examples of organic titanium derivatives, representative arethose of the formulae: ##STR41##

    (CH.sub.3).sub.2 CHO.sub.4 Ti,

    (n--C.sub.3 H.sub.7 O).sub.4 Ti,

    (n--C.sub.8 H.sub.17 O).sub.4 Ti,

    (CH.sub.3 CH.sub.2 OCH.sub.2 CH.sub.2 O).sub.4 Ti,

    (CH.sub.3 OCH.sub.2 CH.sub.2 O).sub.4 Ti

    [.sub.3 (CH.sub.2).sub.3 CH(C.sub.2 H.sub.5)CH.sub.2 O].sub.4 Ti

These organic titanium derivatives are described, in particular, inFrench Pat. Nos. 1,330,625, 2,121,289 and 2,121,631.

As specific examples of organic zirconium derivatives, representativeare those of the formulae:

    (C.sub.2 H.sub.5 O).sub.4 Zr

    [CH.sub.3).sub.2 CHO].sub.4 Zr

    (n--C.sub.3 H.sub.7 O).sub.4 Zr

    (n--C.sub.4 H.sub.9 O).sub.4 Zr

    (CH.sub.3).sub.3 C--O).sub.4 Zr

    (CH.sub.3 OCH.sub.2 CH.sub.2 O).sub.4 Zr

    (n--C.sub.7 H.sub.15 O).sub.4 Zr.

Other single-component base compositions may also be prepared by mixing:

(A³): 100 parts of a diorganopolysiloxane polymer of the formula:

    W.sub.3-h M.sub.h Si(OSiT.sub.2).sub.p OSiM.sub.h W.sub.3-h

in which the symbols T, which are identical or different, representhydrocarbon radicals containing from 1 to 10 carbon atoms which areeither unsubstituted or substituted by halogen atoms or cyano groups,the symbols M, which are identical or different, represent halogenatedor nonhalogenated C₁ -C₁₀ hydrocarbon radicals, the symbols W, which areidentical or different, represent alkoxy or polyalkoxy radicals of theformulae Z³ O, or Z³ OE² O--, in which the symbol Z³ represents a C₁ -C₄alkyl radical, the symbol E² a C₂ -C₄ alkylene radical, the symbol h iszero or one and the symbol p represents a number whose value issufficient to provide a viscosity of 700 to 1,000,000 mPa.s at 25° C.

(B³): 0 to 15 parts of a polyalkoxysilane of the formula M_(h)SiW_(4-h), in which the symbols W, M and h have the meanings of thesymbols W, M and h of the diorganopolysiloxane polymer (A³),

(C³): 0 to 250 parts of inorganic fillers, and

(D³): 0 to 20 parts of compounds selected from among:

1. primary or secondary organic amines which have a pK_(b) of less than5 in aqueous medium, aminoorganosilanes, aminoorganopolysiloxanes andguanidinoorganosilanes containing, per molecule, both:

(i) at least one C₁ -C₁₅ organic group bonded to the silicon atom via aSi-C bond and substituted by at least one amino radical or a guanidinoradical, and

(ii) at least one C₁ -C₅ alkoxy radical or a C₃ -C₆ alkoxyalkylenoxyradical, or

2. organic titanium and zirconium derivatives containing organoxy and/orβ-(diketonato) groups.

The diorganopolysiloxane polymer (A³) is prepared by contacting anα,ω-dihydroxydiorganopolysiloxane polymer of the formula:

    HO(T.sub.2)Si(OSiT.sub.2).sub.p-2 OSi(T.sub.2)OH

with the polyalkoxysilane (B³) of the formula M_(h) SiW_(4-h) in aproportion of at least two moles of polyalkoxysilane per one mole ofα,ω-dihydroxydiorganopolysiloxane polymer.

The reaction may be carried out in the presence of an organic amine(U.S. Pat. No. 3,542,901), an organic titanium derivative (U.S. Pat. No.4,111,890) or an N,N-disubstituted hydroxylamine (French Pat. No.2,508,467).

The symbol T in the formula of the polymer (A³) has the meaning of thesymbol T in the formula T₂ SiO of the recurring units in the polymer(A¹), described above. The symbols M, W, Z³ and E², which belong to theformula of the polymer (A³) and to that of the polyalkoxysilane (B³)have, respectively, the meaning of the symbols M, W, Z³ and E² in theformula of the polyalkoxysilane (B²), described above.

Consequently, representative examples which have already been given forthe various radicals represented by the symbols in (B²), also apply tothe radicals represented by the symbols in (A³) and in (B³).

By way of illustration, the diorganopolysiloxane polymers (A³) may beblocked at each end of their polymer chain by units of the formulae:

    (CH.sub.3 O).sub.2 CH.sub.3 SiO.sub.0.5

    (CH.sub.3 O).sub.3 SiO.sub.0.5

    (CH.sub.3 O CH.sub.2 CH.sub.2 O).sub.2 CH.sub.3 SiO.sub.0.5

    (CH.sub.3 CH.sub.2 OCH.sub.2 CH.sub.2).sub.2 CH.sub.2 CH.sub.3 SiO.sub.0.5

    (CH.sub.3 OCH.sub.2 CH.sub.2 O).sub.3 SiO.sub.0.5 ##STR42##

The recurring units in the polymer chain correspond, for example, to theformulae:

    (CH.sub.3).sub.2 SiO

    CH.sub.3 (CH.sub.2 ═CH)SiO

    (C.sub.6 H.sub.5).sub.2 SiO

    CH.sub.3 (CF.sub.3 CH.sub.2 CH.sub.2)SiO

The polyalkoxysilane (B³), used in a proportion of 0 to 15 parts per 100parts of polymer (A³), preferably 0.5 to 13 parts, is similar to thepolyalkoxysilane (B²); thus, the formulae mentioned as examples for (B²)are also applicable to the polyalkoxysilane (B³).

The inorganic fillers (C³) are identical to the fillers (C¹), describedabove. They are used in a proportion of 0 to 250 parts, preferably 5 to200 parts per 100 parts of polymer (A³).

The compounds (D³) are used in a proportion of 0 to 20 parts, preferably2 to 18 parts per 100 parts of polymer (A³). They include, inparticular, primary and secondary organic amines, aminoorganosilanes,aminoorganopolysiloxanes and organic titanium and zirconium derivatives;these compounds are similar to the compounds (D²) described above, andas a result the description given in the case of the compounds (D²) isalso applicable to the compounds (D³). In addition, the compounds (D³)include the guanidinoorganosilanes and guanidino organopolysiloxanesdescribed, for example, in U.S. Pat. No. 4,180,642.

Exemplary of such guanidinoorganosilanes and siloxanes, representativeare those of formulae: ##STR43##

All three types of single-component base compositions immediately abovedescribed are catalyzed by the addition of the organic tin systemaccording to the invention, obtained by mixing the chelated derivativewith the nonchelated derivative. The amount of the organic tin systemwhich is used per 100 parts of the base composition is on the order of0.0001 to 5 parts, preferably 0.001 to 4.5 parts.

Apart from the single-component base compositions, it is possible to usetwo-component base compositions which cure as soon as the organic tinderivative has been incorporated. After the incorporation of the tincatalyst, they are packaged as two separate fractions, where one of thefractions contains, for example, only the tin catalyst or the lattermixed with the crosslinking agent.

These base compositions are produced by mixing:

(A⁴): 100 parts of an α,ω-dihydroxydiorganopolysiloxane polymer havingviscosity of 700 to 1,000,000 mPa.s at 25° C.,

(B⁴): 1 to 20 parts of:

(i) a silane of the formula (R¹⁷)_(k) Si(OR¹⁶)_(4-k), in which thesymbols R¹⁶, which are identical or different, represent C₁ -C₈ alkylradicals, C₃ -C₆ alkoxyalkylene radicals, the symbol R¹⁷ represents a C₁-C₁₀ hydrocarbon radical and the symbol k is zero or one, or

(ii) products of partial hydrolysis of the silane of the formulaSi(OR¹⁶)₄, in which the symbol R¹⁶ has the meaning given under (i), and

(C⁴): 0 to 150 parts of inorganic fillers.

The α,ω-dihydroxydiorganopolysiloxane polymer (A⁴) is similar to theα,ω-dihydroxydiorganopolysiloxane polymer (A¹) described above inconnection with the preparation of single-component bases.

This polymer (A⁴) has a viscosity of 700 to 1,000,000 mPa.s at 25° C.,preferably 1,000 to 800,000 mPa.s at 25° C.; the organic radicals bondedto the silicon atoms are preferably methyl, ethyl, propyl, vinyl orphenyl radicals. Copolymers containing at least 80% of methyl radicalsare generally selected.

The silane (B⁴) of formula R¹⁷ _(k) Si)OR¹⁶)_(4-k) is used in aproportion of 1 to 20 parts, preferably 2 to 15 parts per 100 parts ofthe polymers (A⁴).

The symbols R¹⁶ represent:

(i) C₁ -C₈ alkyl radicals, such as methyl, ethyl, propyl, butyl, pentylor 2-ethylhexyl radicals, or

(ii) C₃ -C₆ alkoxyalkylene radicals, such as those of the formulae:

    CH.sub.3 OCH.sub.2 CH.sub.2 --

    CH.sub.3 OCH.sub.2 CH(CH.sub.3)--

    CH.sub.3 OCH(CH.sub.3)CH.sub.2 --

    C.sub.2 H.sub.5 OCH.sub.2 CH.sub.2 CH.sub.2 --

The symbol R¹⁷ represents a C₁ -C₁₀ hydrocarbon radical which includes:

(i) C₁ -C₁₀ alkyl radicals, such as methyl, ethyl, propyl, butyl,pentyl, 2-ethylhexyl, octyl or decyl radicals,

(ii) vinyl or allyl radicals,

(iii) C₅ -C₈ cycloalkyl radicals, such as cyclopentyl or cyclohexylradicals, and

(iv) monocyclic C₆ -C₈ aryl radicals, such as phenyl, tolyl or xylylradicals.

The products of partial hydrolysis of the silane of the formulaSi(OR¹⁶)₄ consist essentially of recurring units of the formula (R¹⁶ O)₂SiO, the remaining recurring units having the formulae (R¹⁶ O)₃ SiO₀.5,(R¹⁶ O)SiO₁.5 or SiO₂.

These products of partial hydrolysis, usually referred to as alkylpolysilicates, dissolve in the usual hydrocarbon solvents, such astoluene, xylene, cyclohexane or methylcyclohexane; the most commonlyused product is ethyl polysilicate 40 which has a silica content of 40%,the value being obtained after total hydrolysis of the OC₂ H₅ radicals.

As specific examples of silanes of formula R¹⁷ _(k) Si(RO¹⁶)_(4-k),representative are those of the formulae:

    CH.sub.3 Si(OCH.sub.3).sub.3

    CH.sub.3 Si(OC.sub.2 H.sub.5).sub.3

    C.sub.2 H.sub.5 Si(OCH.sub.3).sub.3

    CH.sub.2 ═CHSi(OCH.sub.3).sub.3

    CH.sub.2 ═CHSi(OCH.sub.2 CH.sub.2 OCH.sub.3).sub.3

    C.sub.6 H.sub.5 Si(OCH.sub.3).sub.3

    CH.sub.3 Si(OCH.sub.3).sub.2 [OCH(CH.sub.3)CH.sub.2 OCH.sub.3 ]

    Si(OCH.sub.3).sub.4

    Si(OC.sub.2 H.sub.5).sub.4

    Si(O--n--C.sub.3 H.sub.7).sub.4

    Si(O--n--C.sub.4 H.sub.9).sub.4

The fillers (C⁴) are used in a proportion of 0 to 150 parts, preferably5 to 120 parts, per 100 parts of the polymers (A⁴). They are identicalto the fillers which have already been described (C¹), used for thepreparation of single-component base compositions.

As above-indicated, the two-component base compositions are catalyzed byaddition of the organic tin system produced by mixing the chelatedderivative with the nonchelated derivative; the amount used is in therange from 0.01 to 10 parts, preferably 0.1 to 8 parts, per 100 parts ofthe two-component base composition.

Other ingredients may be introduced in addition to the principalconstituents of the single-component and two-component basecompositions, that is to say, (1) the diorganopolysiloxane polymers (A¹)to (A⁴) which are blocked by a hydroxyl radical and/or alkoxy radicalsat the end of the polymer chain, (2) organosilicon crosslinking agents(B¹) to (B⁴) containing hydrolyzable groups, (3) the inorganic fillers(C¹) to (C⁴) and (4) the adhesion promoters (D¹) and the compounds (D²)and (D³).

These ingredients include organosilicon compounds, chiefly polymers,which are capable of modifying the physical characteristics of thecompositions according to the invention (which are produced by mixingthe bases with the tin catalyst) and/or the mechanical properties of thesilicone elastomers produced from these compositions.

These compounds are well known and include, for example:

(i) α,ω-bis(triorganosiloxy)diorganopolysiloxane polymers having aviscosity of at least 10 mPa.s at 25° C., in which the organic radicalsbonded to the silicon atoms are selected from among methyl, vinyl orphenyl radicals, preferably at least 80% of the radicals being methylradicals and not more than 3% being vinyl radicals;α,ω-bis(trimethylsiloxy)dimethylpolysiloxane oils having a viscosity of10 mPas. at 25° C. to 1,500 mPa.s at 25° C. are preferably used,

(ii) liquid, branched methyl polysiloxane polymers containing from 0.1to 8% of hydroxyl groups bonded to the silicon atoms, including (CH₃)₃SiO₀.5, (CH₃)₂ SiO and CH₃ SiO₁.5 recurring units distributed such as toprovide a ratio (CH₃)₃ SiO₀.5 /(CH₃)₂ SiO of 0.01 to 0.15 and a ratioCH₃ SiO₁.5 /(CH₃)₂ SiO of 0.1 to 1.5,

(iii) α,ω-di(hydroxy)dimethylpolysiloxane oils having a viscosity of 10to 300 mPa.s at 25° C. and α,ω-di(hydroxy)methylphenylpolysiloxane oilshaving a viscosity of 200 to 1,000 mPa.s at 25° C., and

(iv) diphenylsilanediol and 1,1,3,3-tetramethyldisiloxanediol.

The above α,ω-bis(triorganosiloxy)diorganopolysiloxane polymers may becompletely or partially replaced with organic compounds which are inerttowards the various constituents of the base compositions and which aremiscible at least with the diorganopolysiloxane polymers (A¹) to (A⁴).As specific examples of these organic compounds, representative are thepolyalkylbenzenes obtained by alkylation of benzene with long-chainolefins, especially the olefins containing 12 carbon atoms produced bypropylene polymerization. Organic compounds of this type are described,for example, in French Pat. Nos. 2,392,476 and 2,446,849.

Each of the above organosilicon compounds may be employed in aproportion of 1 to 100 parts, preferably 3 to 75 parts, per 100 parts ofdiorganopolysiloxanes (A¹) to (A⁴).

Ingredients which are not organosilicon compounds may also beintroduced, for example, heat stabilizers. These compounds improve theheat resistance of the silicone elastomers. They may be selected fromamong carboxylic acid salts, rare earth oxides and hydroxides and, moreespecially, ceric oxides and hydroxides, as well as from pyrogenictitanium dioxide and the various iron oxides. From 0.1 to 15 parts,preferably 0.15 to 12 parts, of heat stabilizers are advantageously usedper 100 parts of the diorganopolysiloxanes (A¹) to (A⁴).

In order to produce the compositions according to the invention, it isnecessary, in the case of the single-component compositions, to use anapparatus which allows the various main constituents, to which theabovementioned adjuvants and additives may be added if desired, to beintimately mixed in the absence of moisture and with or without theintroduction of heat.

All such ingredients may be charged into the apparatus in any order ofaddition. Thus, the diorganopolysiloxaned polymers (A¹) to (A³) and thefillers (C¹ to C³) may be mixed first and then the crosslinking agents(B₁) to (B³), the compounds (D¹) to (D³) and the organic tin system maythen be added to the resulting paste.

It is also possible to mix the polymers (A¹) to (A³), the crosslinkingagents (B¹) to (B³) and the compounds (D¹) to (D³) and then to add thefillers (C¹) to (C³) and the organic tin system. During theseoperations, the mixtures may be heated to a temperature in the range50°-180° C. at atmospheric pressure, or at a reduced pressure, in orderto promote the removal of volatile materials, such as water and lowmolecular weight polymers.

Compositions which are prepared in this manner may be used as such, orin the form of a dispersion in organic diluents. These diluents arepreferably conventional, commercially available materials selected fromamong:

(i) halogenated or non-halogenated aliphatic, alicyclic or aromatichydrocarbons, such as n-heptane, n-octane, cyclohexane,methylcyclohexane, toluene, xylene, mesitylene, cumene, tetralin,decalin, perchloroethylene, trichloroethane, tetrachloroethane,chlorobenzene or orthodichlorobenzene,

(ii) aliphatic and alicyclic ketones, such as methyl ethyl ketone,methyl isobutyl ketone, cyclohexanone or isophorone, and

(iii) esters, such as ethyl acetate, butyl acetate, and ethoxyethylacetate.

The amounts of diluents which are introduced must be sufficient toproduce stable dispersions which spread readily over the substrates.These amounts depend essentially on the nature and on the viscosity ofthe initial organopolysiloxane compositions. Their proportions maytherefore vary widely; nevertheless, it is recommended to producedispersions containing from 15 to 85% by weight of diluents.

The single-component compositions according to the invention, which areused as such, namely, undiluted, or in the form of dispersions indiluents, are stable in storage in the absence of water, and cure atambient temperature and above (after removal of the solvents in the caseof the dispersions) in the presence of water, to form elastomers.

After the compositions as such have been deposited onto solidsubstrates, in a moist atmosphere, it is found that a process of curingto elastomers begins to take place and proceeds from the outside towardsthe interior of the deposited mass. A surface skin forms first and thisis followed by in-depth crosslinking.

The complete skin formation, observed when the surface is no longertacky to the touch, requires a period of time which may be in the rangeof from 1 minute to 55 minutes; this time period depends upon the degreeof relative humidity of the atmosphere surrounding the compositions andon the ease with which they crosslink.

Furthermore, the in-depth cure of the deposited layers, which must besufficient to enable the elastomers formed to be demolded and handled,requires a much longer period of time. In fact, this period depends notonly on the abovementioned factors concerning the formation of anontacky feel, but also on the thickness of the deposited layers, whichgenerally ranges from 0.5 mm to several centimeters. This longer periodof time may last from 10 minutes to 20 hours.

The single-component compositions may be employed for numerousapplications, such as sealing in the building industry, assembly of avery wide variety of materials (metals, plastics, natural and syntheticrubbers, wood, cardboard, crockery, brick, ceramic, glass, stone,concrete, masonry components), insulation of electrical conductors,coating of electronic circuits, and the preparation of molds used forthe production of articles made of synthetic resins or foams.

The above-mentioned dispersions of these compositions in the diluentsmay be employed for impregnating inorganic, synthetic, organic,metallic, woven or nonwoven products and articles in thin layers, andfor coating sheets consisting of metal, plastics or cellulose-basedsubstances. The deposition may be carried out, for example, by dippingor by spraying; in the latter case, a paint spray gun which enablesuniform coatings with a thickness of 5 to 300 μm to be obtained is used.After the dispersions have been sprayed on, the diluents evaporate offand the compositions which are released cure to a rubbery film.

The production of the two-component compositions according to theinvention is also carried out by mixing the various constituents insuitable apparatus. To obtain homogeneous compositions, it is preferableto first mix the polymers (A⁴) with the fillers (C⁴); the combinationmay then be heated for at least 30 minutes at a temperature above 80° C.to ensure that the fillers are completely wetted by the oils. The otherconstituents, that is to say, the crosslinking agents (B⁴), the organictin system, and, if desired, the various additives and adjuvants andeven water, may then be added to the resulting mixture, which ispreferably heated to a temperature below 80° C., for example, on theorder of ambient temperature.

Such compositions are not stable in storage and must consequently beused promptly, for example, within a 40 minute period.

The various additives and adjuvants are the same as those introducedinto the single-component compositions. Once again, particular mentionmust be made of α,ω-bis(triorganosiloxy)diorganopolysiloxane polymershaving a viscosity of at least 10 mPa.s at 25° C., in which the organicradicals bonded to the silicon atoms are methyl, vinyl and phenylradicals. α,ω-Bis(trimethylsiloxy)dimethylpolysiloxane oils having aviscosity preferably from 20 mPa.s at 25° C. to 1,000 mPa.s at 25° C.are preferably employed.

To promote the cure of two-component compositions which are used in theform of thick layers, the thickness of which is, for example, greaterthan 2 cm, it is recommended to introduce water in a proportion notexceeding 1 part per 100 parts of the polymers (A⁴).

This water addition is unnecessary, if a sufficient amount of it isalready present in the fillers (C⁴). To make it easier to incorporate,the water is preferably added in the form of a dispersion in a paste of,for example, the abovementionedα,ω-bis(triorganosiloxy)diorganopolysiloxane oils and the fillers (C⁴).

For packaging and storage, the two-component compositions thereforecannot contain all of the principal constituents, namely, the polymers(A⁴), the crosslinking agent (B⁴), the fillers (C⁴) and the organic tinsystem. On an industrial scale, they must be manufactured in the form oftwo components, both of which are stable when stored.

A first component, which is stable in storage, may comprise, forexample, the constituents (A⁴), (B⁴) and (C⁴); it is preferably preparedby adding the crosslinking agents (B⁴) to the homogeneous mixtureproduced by kneading the polymers (A⁴) with the fillers (C⁴).

The second component then comprises the organic tin system.

Other ways of formulating the two-component compositions may beselected: for example, a first component containing the polymers (A⁴)and the fillers (C⁴), and a second component containing the crosslinkingagents (B⁴) and the organic tin system.

In many applications, it is preferable that both components should besufficiently fluid such that when they are mixed they readily formcompositions whose viscosity ranges, for example, from 10,000 to 800,000mPa.s at 25° C.

These compositions, which remain sufficiently fluid for at least 40minutes, preferably for at least 80 minutes, after the two componentshave been mixed, may be used more especially for the manufacture ofmolds made of silicone elastomers; they may, however, be used for otherapplications, such as the covering of electronic hardware and thecoating of metal, textile or cellulose-based surfaces.

The molds which are manufactured are intended to reproduce articles madeof cellular or other materials consisting of organic polymers. Amongthese materials, exemplary are the polyurethanes, polyesters, polyamidesand polyvinyl chloride. It is recommended, however, to use these moldsfor the reproduction of polyurethane articles, in view of the fact thatthey resist corrosion by the constituents of the mixtures (especially bypolyisocyanates) used to produce polyurethane materials.

The introduction of a catalyst according to the invention, based on anorganic tin derivative, enables optimum application conditions to beobtained with the single- and two-component compositions. It then makesit possible to produce elastomers having tensile properties which arestable with time and independent of the age and of the storageconditions of the compositions.

In order to further illustrate the present invention and the advantagesthereof, the following specific examples are given, it being understoodthat same are intended only as illustrative and in nowise limitative. Insaid examples to follow, all parts and percentages are by weight, unlessotherwise indicated.

EXAMPLE 1

A composition P₁ was prepared by mixing:

(i) 100 parts of an α,ω-dihydroxydimethylpolysiloxane oil having aviscosity of 10,000 mPa.s at 25° C.,

(ii) 70 parts of an α,ω-bis(trimethylsiloxy)dimethylpolysiloxane oilhaving a viscosity of 800 mPa.s at 25° C.,

(iii) 55 parts of a pyrogenic silica having a specific surface area of300 m² /g, treated with hexamethyldisilazane,

(iv) 50 parts of ground quartz having a mean particle diameter of 5micrometers, and

(v) 10 parts of a paste made from 90 parts ofα,ω-dihydroxydimethylpolysiloxane oil, mentioned above, having aviscosity of 10,000 mPa.s at 25° C., 5 parts of a pyrogenic silicahaving a specific surface area of 150 m² /g and 5 parts of water.

A crosslinking system C₁ was prepared by mixing, at ambient temperature,82.5 parts of an ethyl polysilicate containing 40% of silica with 17.5parts of an organic tin mixture. The organic tin mixture consisted ofdi-n-butyltin dilaurate or of the tin chelate (CR₁) or a combination ofdi-n-butyltin dilaurate with the tin chelate (Ch₁) of the formula:##STR44##

The combination contained 75%, 50% or 25% by weight of either of theconstituents.

The composition P₁ was catalyzed by mixing 100 parts of this compositionwith two parts of the crosslinking system C₁. The latter was used assuch, freshly prepared, or after it had been subjected to aging at 70°C. for a period of 66 hours, 185 hours or 329 hours.

The spreading time of the catalyzed composition was then determined bynoting the period of time during which this composition was in asufficiently fluid state to spread under its own weight and thus toadopt the configuration of the internal space of the containers intowhich it was poured.

The test employed for assessing spreadability was the following:

The freshly catalyzed composition (15 grams) was poured into acylindrical aluminum dish 4 cm in diameter; after a period not exceeding5 minutes, it must have a surface which is perfectly horizontal.

After several hours at ambient temperature, the catalyzed compositionwas converted into a silicone elastomer; the Shore A hardness of theformed elastomer was measured 24 hours after the preparation of thiscatalyzed composition. The results relating to the spreading time andthe Shore A hardness values are reported in Table 1 below:

                                      TABLE 1                                     __________________________________________________________________________    Composition of                                                                        Di-N--butyltin                                                                        100       75       50       25        0                       the organic tin                                                                       dilaurate                                                             system (in % by                                                                       Tin chelate                                                                            0        25       50       75       100                      weight) (CH.sub.1)                                                            __________________________________________________________________________                                   Shore    Shore    Shore                                        Spread                                                                             Shore                                                                              Spread                                                                             A   Spread                                                                             A   Spread                                                                             A   Spread                                                                             Shore               Aging period of the crosslinking                                                              time A hard-                                                                            time hard-                                                                             time hard-                                                                             time hard-                                                                             time A hard-             system C.sub.1 at 70° C. (in hours)                                                    (in min)                                                                           ness (in min)                                                                           ness                                                                              (in min)                                                                           ness                                                                              (in min)                                                                           ness                                                                              (in                                                                                ness                __________________________________________________________________________     0              170  20   184  18  178  18  198  17  300  5                    66             190  18   164  18  180  18  190  18  360  5                   185             100  20   103  21  146  20  168  19  400  5                   329              84  20    85  20  125  20  148  19  400  5                   __________________________________________________________________________

It was found that the spreading times became markedly shorter when theperiod of aging of the crosslinking system C₁ at 70° C. exceeded 66hours. However, the magnitude of this change depended on the compositionof the organic tin system. When this system was di-n-butyltin dilaurate,a 50% drop in spreading time was noted after 329 hours at 70° C.; whenthis system was a mixture of 25% of di-n-butyltin dilaurate and 75% oftin chelate (Ch₁), the drop was greatly attenuated and barely exceeded25%. In the absence of di-nbutyltin dilaurate, it was found that theShore A hardness was very clearly inadequate for a thorough cure.

EXAMPLE 2

A composition P₂ was prepared by mixing:

(i) 100 parts of an α,ω-dihydroxydimethylpolysiloxane oil having aviscosity of 20,000 mPa.s at 25° C.,

(ii) 100 parts of an α,ω-bis(trimethylsiloxy)dimethylpolysiloxane oilhaving a viscosity of 500 mPa.s at 25° C.,

(iii) 50 parts of a pyrogenic silica having a specific surface area of200 m² /g, treated with hexamethyldisilazane,

(iv) 100 parts of ground quartz having a mean particle diameter of 5 μm,and

(v) 15 parts of the paste containing 5% of water, heretofore employed asa constituent of the composition of Example 1.

The composition P₂ was catalyzed by mixing 100 parts of this compositionwith 2 parts of a crosslinking system C₂, similar to the crosslinkingsystem C₁ used in Example 1, that is to say, consisting of 82.5 parts ofalkyl polysilicate and 17.5 parts of an organic tin derivative. Theorganic tin system consisted of di-n-butyltin dilaurate or of acombination containing, by weight, 50% of di-n-butyltin dilaurate, 35%of tin chelate (Ch₁) of the formula: ##STR45## and 15% of tin chelate(Ch₂) of the formula: ##STR46## The crosslinking agent C₂ was used assuch, freshly prepared, or after having been subjected to aging for 2,6, 9, 10 and 12 days at 75° C.

The spreading time of the catalyzed composition was determined asindicated in Example 1; the Shore A hardness of the silicone elastomerobtained was also determined, 24 hours after the forming of thecatalyzed composition. The results are reported in Table 2 below;

                                      TABLE 2                                     __________________________________________________________________________    Composition of                                                                        Di-n-butyltin                                                                           100       50                                                the organic tin                                                                       dilaurate                                                             system (in % by                                                                       Tin Chelate (CH.sub.1)                                                                  0         35                                                weight) Tin Chelate (CH.sub.2)                                                                  0         15                                                __________________________________________________________________________    Aging period of the cross-                                                                      Spread                                                                             Shore                                                                              Spread                                                                             Shore                                        linking system C.sub.2 at 70° C.                                                         time A hard-                                                                            time A hard-                                      (in days)         (in min)                                                                           ness (in min)                                                                           ness                                         __________________________________________________________________________    0                 60   16   64   17                                           2                 66   17   79   14                                           6                 37   18   67   17                                           9                           55   17                                           10                24   18                                                     12                20   18   45   17                                           __________________________________________________________________________

It was found that the spreading times became shorter when the aging timeof the crosslinking system reached 6 days or more. This drop was veryconsiderable, on the order of 70% after 12 days, in the case where anorganic tin system containing di-n-butyltin dilaurate was used; it wasonly 30% in the case where a mixed system containing the combination ofdi-n-butyltin dilaurate with 2 diorganotin chelates was used.

EXAMPLE 2b

100 parts of the composition P₁ used in Example 1 were catalyzed with 5parts of a crosslinking system C₃ similar to the crosslinking system C₁used in Example 1; the organic tin system consisted of di-n-butyltindilaurate and of its combination, in the weight ratio 50/50, with thechelate Ch₁ of the formula: ##STR47##

The catalyzed composition was deposited onto a polyethylene plaque inthe form of a layer 2 mm in thickness. After a period of rest of 24hours open to the atmosphere, the formed elastomer film was demolded andpermitted to age for a variable number of days at a temperature of 20°C.

The Shore A hardness (SAH) and the tear strength (TS) (expressed inkN/m) of the film which had been subjected to the abovementioned agingtimes, were measured. The results are reported in Table 3 below:

                  TABLE 3                                                         ______________________________________                                        Composition of                                                                          Di-n-butyltin 100        50                                         the organic tin                                                                         dilaurate                                                           system (in % by                                                                         Tin Chelate (CH.sub.1)                                                                       0         50                                         weight)                                                                       ______________________________________                                        Aging period of the 2 mm thick films                                          at 25° C.    SAH    TS      SAH  TS                                    ______________________________________                                        1 day               26     --      26   --                                    10 days             37     11      38   13                                    30 days             32     14      33   13                                    60 days             39     7.5     38   11                                    90 days             39     7       38    9                                    150 days            39     6       38    8                                    ______________________________________                                    

After the elastomers had been aged for 60 days at ambient temperature, amarked reduction in the value of the tear strength was found in the casewhere an organic tin system consisting solely of di-n-butyltin dilauratewas used. This decrease did not take place when a 50/50 by weightcombination of dibutyltin dilaurate and tin chelate (Ch₁) was used.

EXAMPLE 3

A crosslinking system C₄, similar to the crosslinking system C₁described in Example 1, was prepared by mixing, at ambient temperature,82.5 parts of an ethyl polysilicate containing 40% of silica with 17.5parts of an organic tin system. This system was a di-n-butyltindiversatate (versatic acid is a saturated synthetic monocarboxylic acid,tertiary in the alpha position relative to the carboxyl group,consisting of a mixture of C₉, C₁₀ and C₁₁ acids), or the combination,in a 50/50 ratio by weight, of such di-n-butyltin diversatate with thechelate Ch₁ of the formula: ##STR48##

The composition P₁ described in Example 1 was then catalyzed by mixing100 parts of this composition with 5 parts of the crosslinking system C₄; the spreading time of the catalyzed composition was determined asindicated in Example 1. Two determinations of Shore A hardness of thesilicone elastomer produced by curing the catalyzed composition weremade by performing measurements on one face surface of a specimen ofelastomer which had cured in the absence of air and on another facesurface which had cured in ambient air. The specimen was produced bycasting the catalyzed composition, over a height of 4 cm, into acylindrical aluminum flask 4 cm in diameter, the casting being followedby curing to elastomer. This wa demolded after 24 hours and theelastomer specimen was used for measuring the Shore A hardness of theconfined face which was in contact with the bottom of the aluminum flaskand the Shore A hardness of the face which was exposed to the ambientair.

Furthermore, other types of specimens, which were films of elastomer 2mm in thickness, produced according to the method described in Example2b, were permitted to age at 20° C. The Shore A hardness (SAH) and thetear strength (TS) (expressed in kN/m) were measured on specimens whichhad been subjected to aging periods of 10, 30, 60, 90 and 150 days.

The results are reported in Tables 4 and 5 below:

                  TABLE 4                                                         ______________________________________                                        Composition of the organic                                                                     Di-n-butyltin                                                                             50    100                                        tin system in % by weight                                                                      diversatate                                                                   Chelate CH.sub.1                                                                          50     0                                         ______________________________________                                        Properties measured:                                                          Spread time in minutes:  35    40                                             Shore A hardness, confined face:                                                                       14     7                                             Shore A. hardness, face exposed to                                                                     25    13                                             ambient air:                                                                  ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Catalyst mixture (in %                                                                     Di-n-butyltin                                                                             100       50                                         by weight)   diversatate                                                                   Chelate (CH.sub.1)                                                                         0        50                                         ______________________________________                                        Aging time (in days) SAH    TS     SAH  TS                                    ______________________________________                                        10 days              32     21     36   24                                    30 days              31     20     33   22                                    60 days              33     16     38   19.5                                  90 days              34     15     38   20                                    150 days             34     10     38   14.5                                  ______________________________________                                    

It was noted that, when employed alone, di-n-butyltin diversatate didnot enable production of an elastomer having an acceptable Shore Ahardness after 24 hours; in particular, the confined face barelyvulcanized after 24 hours, could not withstand the normal demoldinghandling without tearing.

After aging, at the end of 60 days, it appeared that di-n-butyltindiversatate alone produced an elastomer which had a SAH and especially aTS which were lower than those produced by its combination with thechelate Ch₁.

EXAMPLE 4

The following materials were ground wet in a kneader:

(i) 100 parts of an α,ω-dihydroxydimethylpolysiloxane oil having aviscosity of 175,000 mPa.s at 25° C.,

(ii) 20 parts of a bis(trimethylsiloxy)dimethylpolysiloxane oil having aviscosity of 100 mPa.s at 25° C.,

(iii) 60 parts of calcium carbonate having a mean particle diameter of 5micrometers, and

(iv) 10 parts of pyrogenic silica having a specific surface area of 150m² /g.

When the mass was homogeneous, added thereto was all of the solutionproduced by mixing 5.5 parts of silane of the formula Si(OCH₂ CH₂OCH₃)4, 2.5 parts of silane of the formula (CH₃ O)₃ Si(CH₂)₃ NH--CH₂ CH₂NH₂ and 0.035 part of the organic tin system which was prepared bymixing dibutyltin dilaurate with the tin chelate (Ch₃) of the formula:##STR49## in a 50/50 molar ratio.

The single-component composition obtained in this manner was stored inthe absence of moisture in sealed aluminum tubes; another compositionwas prepared which was identical to the above, except that onlydibutyltin dilaurate was used as the organic tin system, the amount usedbeing identical, i.e., 0.035 part.

This composition was also packaged in sealed aluminum tubes. The storagestability of both compositions was checked; for this purpose, the tubescontaining them were left for 72 hours in an oven heated to 100° C.

The tubes were allowed to cool and their contents were spread out(together with the contents of the tubes which had not been subjected toa period of heating and which had undergone storage for period of 1month at ambient temperature) in the form of a layer 2 mm in thickness,in the open air, on a polytetrafluoroethylene plaque. The depositedlayer was converted into a rubbery film; 24 hours after the depositionof the layer, the elastomer film was stripped and the tensile propertiesof the elastomers were measured after an aging period of 7 days atambient temperature.

The results are reported in Table 6 below:

                                      TABLE 6                                     __________________________________________________________________________             Tensile                                                                       Compositions catalyzed with the tin                                           systems produced by mixing di-                                                n-butyltin dilaurate with the                                                                    Compositions catalyzed with                                chelate CH.sub.3   di-n-butyltin dilaurate                                    Properties                                                                    Content of the     Content of the                                             tubes stored at                                                                        Content of the                                                                          tubes stored at                                                                        Content of the                                    ambient tempera-                                                                       tubes aged for                                                                          ambient tempera-                                                                       tubes aged for                                    ture     72 hours at 100° C.                                                              ture     72 hours at 100° C.               __________________________________________________________________________    Shore A hardness                                                                       16       15        15       9                                        Tensile Strength                                                                       1.28     1.05      1        0.7                                      (in MPa)                                                                      Elongation                                                                             630      490       650      530                                      at break (in %)                                                               __________________________________________________________________________

Inspection of the values of the tensile properties clearly indicate thatin order to retain these properties over time, it is advantageous to usethe di-n-butyltin dilaurate/chelate (Ch₃) catalyst mixture rather thanthe di-n-butyltin dilaurate alone.

While the invention has been described in terms of various preferredembodiments, the skilled artisan will appreciate that variousmodifications, substitutions, omissions, and changes may be made withoutdeparting from the spirit thereof. Accordingly, it is intended that thescope of the present invention be limited solely by the scope of thefollowing claims, including equivalents thereof.

What is claimed is:
 1. An organopolysiloxane composition of matter,which comprises a vulcanizable organopolysiloxane base composition andan organotin curing catalyst therefor, said organotin curing catalystcomprising admixture of (i) a diorganotin bis(β-diketonate) and (ii) anorganotin (IV) compound devoid of β-diketonate functional group andcontaining at least one tin atom, each such tin atom bearing two organicradicals bonded thereto via a Sn--C bond, with each of the two remainingvalencies being satisfied by organic or inorganic radicals bondedthereto via a Sn--O or Sn--S bond, by halogen atoms, by hydroxyl groupsor by oxygen atoms, said organotin curing catalyst being present in anamount effective to cure said vulcanizable organopolysiloxane basecomposition.
 2. The organopolysiloxane composition of matter as definedby claim 1, said organotin curing catalyst comprising from 0.1 to 99.9%by weight of the diorganotin bis(β-diketonate) and from 99.9% to 0.1% byweight of the organotin (IV) compound devoid of β-diketonato functionalgroup.
 3. The organopolysiloxane composition of matter as defined byclaim 1, said diorganotin bis(β-diketonate) having the formula:##STR50## in which R¹ and R², which may be identical or different, areC₁ -C₁₂ organic radicals; R³ and R⁵, which may be identical ordifferent, have the definition of R¹ and R² or are hydrogen atoms,cyanoalkyl radicals containing a C₂ -C₄ alkyl moiety, or cyanoalkoxyradicals containing a C₁ -C₅ alkyl moiety; R⁴ is a hydrogen atom or ahalogenated or nonhalogenated C₁ -C₈ hydrocarbon radical, with theproviso that R⁴ and R⁵ may together form a cyclic C₅ -C₁₂ hydrocarbonradical, or a substituted such radical bearing at least one chloro,nitro or cyano substituent.
 4. The organopolysiloxane composition ofmatter as defined by claim 3, wherein R¹ and R² are halogenated ornonhalogenated C₁ -C₁₂ alkyl radicals.
 5. The organopolysiloxanecomposition of matter as defined in claim 4, said diorganotinbis(β-diketonate) having one of the formulae: ##STR51##
 6. Theorganopolysiloxane composition of matter as defined by claim 1, saidorganotin (IV) compound devoid of β-diketonato functional group havingone of the formulae:

    A.sub.2 SnR.sup.6.sub.2,

    R.sup.6.sub.2 SnO,

    AR.sup.6.sub.2 SnOSnR.sup.6.sub.2 A, or ##STR52## in which R.sup.6 is a halogenated or nonhalogenated C.sub.1 -C.sub.20 hydrocarbon radical; A is an organic or inorganic radical, an organosilicon radical or a polydiorganosiloxane chain, bonded to the tin atom via a Sn--O or Sn--S bond, a halogen atom or a hydroxyl radical; and Q is a C.sub.2 -C.sub.10 alkylene radical.


7. The organopolysiloxane composition of matter as defined by claim 6,said organotin (IV) compound devoid of β-diketonato functional grouphaving one of the formulae:

    A.sub.2 SnR.sup.6.sub.2, or

    R.sup.6.sub.2 SnO

in which R⁶ is a straight or branched chain C₁ -C₂₀ alkyl radical, and Ais a monocarboxylate radical of the formula R⁷ COO, with R⁷ being a C₁-C₂₀ hydrocarbon radical; an alkoxy radical of the formula R⁸ O, inwhich R⁸ is a C₁ -C₈ hydrocarbon radical; a ketiminoxy radical of theformula: ##STR53## in which R¹² and R¹³ are C₁ -C₁₀ hydrocarbonradicals; an organosilicon radical; or a short Chainpolydiorganosiloxane.
 8. The organopolysiloxane composition of matter asdefined by claim 7, said organotin (IV) compound devoid of β-diketonatofunctional group comprising di-n-butyltin dilaurate, di-n-octyltindilaurate, di-n-butyltin diacetate, di-n-octyltin diacetate,di-n-butyltin di-2-ethylhexanoate, di-n-octyltin di-2-ethylhexanoate,di-n-butyltin diversatate, or di-n-octyltin diversatate.
 9. Theorganopolysiloxane composition of matter as defined by claim 2, saidorganotin curing catalyst comprising from 10 to 90% by weight of thediorganotin bis(β-diketonate) and from 90 to 10% by weight of theorganotin (IV) compound devoid of β-diketonato functional group.